This invention relates to robotically-assisted surgical manipulators and more particularly to systems and methods for performing telerobotic surgical procedures on a patient while providing the surgeon with the sensation of physical presence at the surgical site.
In robotically-assisted or telerobotic surgery, the surgeon typically operates a master controller to remotely control the motion of surgical instruments at the surgical site from a location that may be remote from the patient (e.g., across the operating room, in a different room or a completely different building from the patient). The master controller usually includes one or more hand input devices, such as joysticks, exoskeletal gloves or the like, which are coupled to the surgical instruments with servo motors for articulating the instruments at the surgical site. The servo motors are typically part of an electromechanical device or surgical manipulator (xe2x80x9cthe slavexe2x80x9d) that supports and controls the surgical instruments that have been introduced directly into an open surgical site or through trocar sleeves into a body cavity, such as the patient""s abdomen. During the operation, the surgical manipulator provides mechanical articulation and control of a variety of surgical instruments, such as tissue graspers, needle drivers, electrosurgical cautery probes, etc., that each perform various functions for the surgeon, e.g., holding or driving a needle, grasping a blood vessel, or dissecting, cauterizing or coagulating tissue.
This new method of performing telerobotic surgery through remote manipulation has, of course, created many new challenges. One such challenge results from the fact that a portion of the electromechanical surgical manipulator will be in direct contact with the surgical instruments, and will also be positioned adjacent the operation site. Accordingly, the surgical manipulator may become contaminated during surgery and is typically disposed of or sterilized between operations. Of course, from a cost perspective, it would be preferable to sterilize the device. However, the servo motors, sensors, encoders and electrical connections that are necessary to robotically control the motors typically cannot be sterilized using conventional methods, e.g., steam, heat and pressure or chemicals, because they would be damaged or destroyed in the sterilization process.
Yet another challenge with telerobotic surgery systems is that a surgeon will typically employ a large number of different surgical instruments during a procedure. Since the number of instrument holders are limited due to space constraints and cost, many of these surgical instruments will be attached and detached from the same instrument holder a number of times during an operation. In laparoscopic procedures, for example, the number of entry ports into the patient""s abdomen is generally limited during the operation because of space constraints as well as a desire to avoid unnecessary incisions in the patient. Thus, a number of different surgical instruments will typically be introduced through the same trocar sleeve during the operation. Likewise, in open surgery, there is typically not enough room around the surgical site to position more than one or two surgical manipulators, and so the surgeon""s assistant will be compelled to frequently remove instruments from the bolder and exchange them with other surgical tools.
What is needed, therefore, are improved telerobotic systems and methods for remotely controlling surgical instruments at a surgical site on a patient. These systems and methods should be configured for easy sterilization so that they can be reused after the components have been contaminated during an operation. In addition, these systems and methods should be designed to minimize instrument exchange time during the surgical procedure.
The present invention provides systems and methods for performing remote, robotically-assisted surgical procedures on a patient while providing the surgeon with the sensation of physical presence at the surgical site (i.e., telepresence). In particular, a three-component surgical system is provided that includes a non-sterile drive and control component, a sterilizable end effector or surgical tool and an intermediate connector component that includes mechanical elements for coupling the surgical tool with the drive and control component, and for transferring motion from the drive component to the surgical tool. The drive and control component is shielded from the sterile surgical site, the surgical tool is sterilizable and disposable and the intermediate connector is sterilizable and reusable. In this manner, the intermediate connector can be sterilized after a surgical procedure without damaging the motors or electrical connections within the drive and control component of the robotic system.
The drive and control component of the present invention generally includes the drive actuators, e.g., motors, gears or pulleys, etc., and positioning devices that are necessary to articulate the surgical tool at the surgical site. In addition, the drive and control component will usually include the encoders and electrical connectors required to couple the component to a servomechanism to form a master/slave telerobotic surgical system. In a specific configuration of the invention, this component comprises a manipulator assembly having a drive assembly and a multiple degree of freedom manipulator arm. The arm and drive assembly are covered by a sterile drape to effectively shield these components from the sterile surgical field during the operation. In this way, the portion of the system including motors, encoders and fragile electronics does not have to be sterilized because it is separated from the sterile field surrounding the a surgical site.
The intermediate connector includes a sterile adaptor that extends through an opening in the sterile drape to couple the sterile surgical tool with the manipulator arm. The adaptor includes a plurality of motion and electrical feed-throughs for articulating the surgical tool, and for sending electrical signals to and from the tool, e.g., force and torque feedback signals, etc. In one configuration, the intermediate component includes a scope adaptor for coupling a viewing scope, such as an endoscope coupled to a camera mount and a camera, to the manipulator arm. In another configuration, the intermediate connector includes a surgical instrument assembly coupled to the sterile adaptor. The surgical instrument assembly will usually include a surgical tool, which may comprise a variety of articulated tools with end effectors, such as jaws, scissors, graspers, needle holders, micro dissectors, staple appliers, tackers, suction irrigation tools, clip appliers, or non-articulated tools, such as cutting blades, cautery probes, irrigators, catheters or suction orifices.
In a preferred configuration, the surgical instrument assembly will further include a wrist unit for removably coupling the surgical tool to the adaptor on the manipulator assembly. The wrist unit comprises an elongate shaft with a distal wrist coupled to the surgical tool for providing articulation of the tool about the distal wrist. During a surgical procedure, the telerobotic system will usually include a variety of surgical instrument assemblies, each having a wrist unit with a different surgical tool attached. The wrist units can be quickly and easily coupled and decoupled from the manipulator assemblies to facilitate instrument exchange during the procedure. In an exemplary embodiment, the wrist unit is reposable, and it includes a mechanism for counting the number of times the wrist unit is used to inhibit further use of the unit.
The manipulator assembly provides a plurality of degrees of freedom to the wrist unit and surgical tool including pitch and yaw movement of the tool about the wrist, rotation about the wrist shaft axis, axial movement and articulation of the end effector on the surgical tool. In addition, the manipulator assembly preferably provides pitch and yaw motion of the wrist unit and the surgical tool about axes perpendicular to the wrist shaft. The motors of the drive assembly are located proximally from the arm and the intermediate component, which facilitates cleaning, decreases the cost of manufacturing the assembly and decreases the inertia of the surgical tool and wrist unit. In a preferred configuration, the manipulator assembly will include a remote center positioning device, such as a parallelogram linkage, for constraining motion of the wrist unit and/or surgical tool about a desired fixed center of rotation. This fixed center of rotation may be located on the wrist unit shaft, at the distal wrist, or in endoscopic procedures, coincident with the entry incision within the patient""s body.
In an exemplary embodiment, the three-component surgical manipulator of the present invention is part of a telerobotic system in which the surgeon manipulates input control devices and views the operation via a displayed image from a location remote from the patient. The system includes a servomechanism coupled to one or more manipulator assemblies to control the wrist units and surgical tools in response to the surgeon""s manipulation of the input control devices. Position, force, and tactile feedback sensors (not shown) may also be employed to transmit position, force, and tactile sensations from the surgical tools back to the surgeon""s hands as he/she operates the telerobotic system. A monitor is coupled to the viewing scope such that the displayed image of the surgical site is provided adjacent the surgeon""s hands. The image is preferably oriented so that the surgeon feels that he or she is actually looking directly at operating site. This configuration provides the surgeon with telepresence, or the perception that the input control devices are integral with the surgical tools.